Related Experiment Videos
The interaction in vitro between group B meningococci and rabbit polymorphonuclear leukocytes. Demonstration of type
Abstract:
The interaction in vitro between group B meningococci and rabbit polymorphonuclear leukocytes has been described. Phagocytosis did not occur in the presence of normal rabbit serum. Antiserum collected 12-21 days following one subcutaneous inoculation of living log phase meningococci exhibited opsonic activity with type specificity; this opsonic action depended on both heat-labile and heat-stable factors. Following ingestion by granulocytes, meningococci were rapidly killed. These studies suggest that group B meningococcal strains contain specific antiphagocytic surface factors of an as yet unknown chemical nature. Antisera obtained 4 or more wk after immunization showed bactericidal activity with the same type specificity as opsonic activity. This bactericidal activity was also lost after heating and restored by the addition of normal serum. Further studies on opsonins and bactericidins for meningococci may shed light on virulence factors in these microorganisms, and may prove useful for a more precise classification of meningococci according to type rather than group specificity.
Insights
Group B meningococci are not phagocytosed with normal serum. Antiserum provides opsonic and bactericidal activity, suggesting specific antiphagocytic factors on meningococci.
Area of Science:
- Immunology
- Microbiology
- Bacteriology
Background:
- Group B meningococci are a significant cause of bacterial meningitis.
- Understanding the interaction between meningococci and host immune cells is crucial for developing effective treatments and vaccines.
Purpose of the Study:
- To investigate the in vitro interaction between group B meningococci and rabbit polymorphonuclear leukocytes.
- To characterize the opsonic and bactericidal activities of antisera against group B meningococci.
Main Methods:
- In vitro incubation of group B meningococci with rabbit polymorphonuclear leukocytes.
- Assessment of phagocytosis in the presence of normal rabbit serum and specific antisera.
- Evaluation of opsonic and bactericidal activities of antisera, including heat-labile and heat-stable factor analysis.
Main Results:
- Phagocytosis of group B meningococci did not occur with normal rabbit serum.
- Antisera exhibited type-specific opsonic activity, dependent on both heat-labile and heat-stable factors.
- Ingested meningococci were rapidly killed by granulocytes, and antisera showed type-specific bactericidal activity dependent on serum factors.
Conclusions:
- Group B meningococci possess specific antiphagocytic surface factors of unknown chemical nature.
- Opsonins and bactericidins play a role in the host defense against group B meningococci.
- Further research may aid in classifying meningococci by type specificity and understanding virulence factors.